<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <link
    rel="stylesheet"
    href="https://cdnjs.cloudflare.com/ajax/libs/animate.css/4.1.1/animate.min.css"/>
    <style>
        .parent{
            width: 300px;
            height: 400px;
            background-color: #ccc;
            /* 水平居中 */
            margin: 0 auto;
            display: flex;
            align-items: self-end;
        }
         .parent>div{
            width: 60px;
            height: 60px;  
         } 
         
         .parent>div:nth-child(2){
            /* 设置自身在交叉轴对齐方式
            flex-start/end center
             baseline基线对齐 文字对齐
              stretch平铺拉伸 高度取消
             */
            align-self: center;
         }
         
    </style>
</head>
<body>
    <div class="parent">
        <div class="div1" style="background-color: red;">弹性元素1</div>
        <div class="div2" style="background-color: green;">弹性元素2</div>
        <div class="div3" style="background-color: blue;">弹性元素3</div>
    </div>
    <div style="width: 100px; height: 100px; background-color: brown;" class="animate__animated animate__swing">我是animateDIV</div>
</body>
</html>